For the anterior fusion of vertebra segments (fractures, tumors, infections, congenital and post traumatic kyphoses, deformities) a wide variety of plate- as well as rod-systems are available.
Some of the advantages of plate systems such as the one disclosed in PCT/US93/08433, are the relatively small dimensions and the generally easy handling. Important disadvantages of these known plate-system consist therein that the area of fusion cannot actively be set under compression, a great assortment of expensive plate implants, and in the case of deformities no possibilities of correction.
Rod systems, such as the ones disclosed in PCT/US93/10908 or PCT/EP94/01606, do not have the above mentioned disadvantages of the plate-systems, but they are naturally larger in their dimensions and more difficult to handle.
U.S. Pat. No. 4,289,123 discloses an orthopedic appliance which includes a pair of brackets anchored to bone and connected by a pair of rods. However, the disclosed device is bulky and cumbersome to use.